\documentclass[12pt,letterpaper,oneside]{scrbook}

\usepackage{import}

\usepackage{dtcdoc}

\makeindex


\begin{document}

\frontmatter
\import{./}{title.tex}

\clearpage
\thispagestyle{empty}
\import{./}{ack.tex}
\import{./}{forward.tex}
 
\tableofcontents

\mainmatter
% Chapter 1: Overview
\import{./}{enkf_ch1.tex}
% Chapter 2: Building
\import{./}{enkf_ch2.tex}
% Chapter 3: Running 
\import{./}{enkf_ch3.tex}
% Chapter 4: Diagnostics and Tuning
\import{./}{enkf_ch4.tex}
% Chapter 5: Applications
\import{./}{enkf_ch5.tex}
% Chapter 6: Theory and code structure
\import{./}{enkf_ch6.tex}
% Appendix A: Namelist
\appendix
\import{./}{enkf_appendix_A.tex}

\addcontentsline{toc}{chapter}{Bibliography}

\backmatter

\bibliographystyle{abbrv}
\bibliography{references}

\end{document}
